N-(4-bromophenyl)-2-methylpropanamide

Conditions: temp:120.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 500 mL three-neck flask were put 18 g (74 mmol) of N-(4-bromophenyl)isobutyramide obtained in Step 1, 15 g (37 mmol) of 2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide (Lawesson's reagent), and 120 mL of toluene, and the mixture was heated and refluxed at 120° C. for 3 hours. After that, toluene was distilled off to give a yellow oily substance. This oily substance was purified by silica gel column chromatography. Toluene was used as a developing solvent. The resulting fraction was concentrated to give a yellow solid. The resulting solid was collected by suction filtration, and the collected solid was washed with a small amount of methanol to give 13 g of a white solid of N-(4-bromophenyl)isobutyrthioamide in a yield of 70%. The reaction scheme of Step 2 is shown in (b-2) below. In a 500 mL three-neck flask were put After that, toluene was distilled off to give a yellow oily substance This oily substance was purified by silica gel column chromatography The resulting fraction was concentrated to give a yellow solid The resulting solid was collected by suction filtration the collected solid was washed with a small amount of methanol

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 500 mL three-neck flask were put 16 g (90 mmol) of 4-bromoaniline, 11 g (108 mmol) of triethylamine, and 250 mL of tetrahydrofuran (THF), and the mixed solution was stirred. To this mixed solution, a mixed solution of 9.6 g (90 mmol) of isobutyryl chloride and 50 mL of THF was added dropwise under cooling with ice, and the mixture was stirred at room temperature for 12 hours. After the stirring, this mixture was dissolved in chloroform, and washed with water and a saturated aqueous solution of sodium hydrogen carbonate. After the washing, anhydrous magnesium sulfate was added to the organic layer for drying. The resulting mixture was subjected to gravity filtration, and the filtrate was concentrated to give a solid. This solid was washed with hexane to give 18 g of a white solid of N-(4-bromophenyl)isobutyramide in a yield of 82%. The reaction scheme of Step 1 is shown in (b-1) below. In a 500 mL three-neck flask were put under cooling with ice washed with water After the washing, anhydrous magnesium sulfate was added to the organic layer for drying The resulting mixture was subjected to gravity filtration the filtrate was concentrated to give a solid This solid was washed with hexane